Water and oxygen are natural enemies of an organic light-emitting diode, which not only can break an unsaturated bond of a polymer and thus accelerate the aging of the organic material therein, but also can harm the electrode in the organic light-emitting diode. Therefore, the packaging level of the organic light-emitting diode determines the life time thereof and the reliance on environment.
Ultraviolet packaging is a common packaging method employed in the laboratory. It has the advantages of low cost and simple operation, but the ultraviolet glue will contact the organic light-emitting diode during the curing of the ultraviolet glue and have an adverse effect on the organic light-emitting diode. Therefore, it cannot be used for the practical industry.
Frit packaging is a packaging method for connecting a packaging glass and a backing substrate by curing the glass frit. However, in this method, crazing may occur during the curing of the glass frit, and air may enter the organic light-emitting diode from the cracks, thus the life time thereof may be influenced.
Comparing with the above method, the traditional film packaging method may be applied to practical industry, and no air will enter the organic light-emitting diode. However, in the traditional film packaging method, an organic light-emitting diode must be prepared first, and then a film is deposited on the organic light-emitting diode for packaging; the organic light-emitting diode and the film cannot be prepared separately and then packaged, thus the preparation process is complex and the production cost is high.
Therefore, it is desired to provide a composite film which can be prepare separately and be used for packaging an organic light-emitting diode, and a packaging method of the composite film.